With increasing sophistication, economists have been estimating gravity equations for five decades. Robust evidence shows that borders and distance impede trade by much more than tariffs or transport costs can explain. We therefore advocate investigation of other sources of resistance, despite...

The formula approach used in many trade negotiations involves large formula cuts in high tariffs, with flexibilities that allow smaller cuts for selected products. Difficulties in evaluating the effects of these exceptions can create major problems. We use a politicaleconomy welfare function and...